Come February, Walker Art Center plans to strip off its brick skin and warm up with new undies.

The renovation project announced Thursday will remove the burgundy-colored bricks on the outside of the museum's 1971 section, add new weatherproofing and vapor barriers around the exposed core, and then install new bricks of the same color and design.

The center's newer metal-clad addition, which opened in 2005, will not be affected. The project will start Feb. 25 and be finished by December 2013. Galleries will remain open although the building will be surrounded by scaffolding.

The $7 million to $8 million in costs will come from the Walker's contingency fund.

"After 40 years, the bricks are near the end of their natural life span," said Walker spokesman Ryan French. Water has seeped in, causing the bricks to deteriorate from the inside, so that structurally they are not safe.

New insulation will improve the museum's climate control and energy efficiency, while new vapor barriers are expected to extend the life of the exterior brick.

"The hope is that we don't have to do this every 40 years," French said.

Designed by the late Edward Larrabee Barnes, the brick structure was heralded as an icon of minimalist architecture when it opened. Its streamlined galleries and floating walls, which fan out from a central stairwell, became models for the display of contemporary art while its rooftop sculpture terraces inspired similar aeries around the country. Over the years, however, the building has been altered significantly -- its windows plastered over, skylights closed, a graceful stairway removed, the entrance hacked off, and the top-floor restaurant shuttered.

The brick will be disposed of by Mortenson Construction, which is handling the project with HGA Architects and Engineers. Both firms worked on the Walker's 2005 addition.

The museum also reiterated its desire to renovate and upgrade the Minneapolis Sculpture Garden, which it runs in collaboration with the Minneapolis Park and Recreation Board. They applied unsuccessfully for $8 million in state bonding money for the project in the past two bienniums and plan to seek state or other funds again in 2013, French said. The museum is also reviewing ideas for the 4-acre hillside west of its building, where the Guthrie Theater once stood, but "we don't have any firm decisions yet," he said.